D o c u m e n t a t i o n

The ADB is a single-master, multiple-slave serial communications bus
that uses an asynchronous protocol and connects keyboards, graphics
tablets, mouse devices, and other devices to the computer.

The custom ADB microcontroller drives the bus and reads status from
the selected external device. A 4-pin mini-DIN connector connects
the ADB to the external devices.

Notes:
1. The total current available for all devices connected to
the +5 V pins on the ADB and the modem port is 500 mA.
Each device should use no more than 100 mA.
2. The user must hold down a key combination for at least
1 second to allow the ADB microcontroller enough time
to respond to the NMI or hard-reset signal.